usb: hub: Allow reset retry for USB2 devices on connect bounce
authorMathias Nyman <mathias.nyman@linux.intel.com>
Tue, 17 Oct 2017 13:07:33 +0000 (16:07 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 27 Oct 2017 08:39:08 +0000 (10:39 +0200)
commit015e94ead900904d18b686311e2da50b92dd58bd
tree342f0766727eff49fe65ccc4924a6ed88cc623c4
parent1916547b28bdad9ff355bd37dcca504015bf398f
usb: hub: Allow reset retry for USB2 devices on connect bounce

commit 1ac7db63333db1eeff901bfd6bbcd502b4634fa4 upstream.

If the connect status change is set during reset signaling, but
the status remains connected just retry port reset.

This solves an issue with connecting a 90W HP Thunderbolt 3 dock
with a Lenovo Carbon x1 (5th generation) which causes a 30min loop
of a high speed device being re-discovererd before usb ports starts
working.

[...]
[ 389.023845] usb 3-1: new high-speed USB device number 55 using xhci_hcd
[ 389.491841] usb 3-1: new high-speed USB device number 56 using xhci_hcd
[ 389.959928] usb 3-1: new high-speed USB device number 57 using xhci_hcd
[...]

This is caused by a high speed device that doesn't successfully go to the
enabled state after the second port reset. Instead the connection bounces
(connected, with connect status change), bailing out completely from
enumeration just to restart from scratch.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1716332
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/hub.c